1. Field of the Invention
The present disclosure relates generally to the testing of fluids to characterize the settlement of relatively heavy components of the fluidr time. More particularly, embodiments of the disclosure relate to systems and methods that employ non-destructive techniques for monitoring drilling mud samples during static aging tests and/or dynamic flow tests.
2. Background
Rotary drilling techniques used in drilling hydrocarbon wellbores commonly employ a drilling fluid or “mud” to provide lubrication to a drill bit and to carry geologic cuttings from the bottom of the wellbore. The mud is generally circulated down-hole into the wellbore through a drill string, out through the drill bit, and then back up to a surface location through an annulus defined between the drill string and a wall of the wellbore. The mud is also relied upon to exert a hydrostatic pressure on the walls of the wellbore to prevent collapse of the wellbore, and to prevent premature entry of formation fluids into the wellbore. The drilling mud may be selected to have a sufficiently high density to control the inflow of formation fluids into the wellbore and sufficiently low density to permit efficient operation of the drill bit.
Often, heavier components of the drilling mud can (end to settle under the influence of gravity to lower regions of the wellbore in a phenomenon commonly referred to “sag.” In operation, the “sag” of a drilling fluid could present difficulties in circulating the mud, and can prevent the mud from effectively managing the formation pressures. Thus, the sag characteristics of a particular drilling fluid are often characterized in laboratory conditions prior being deployed in a wellbore. For instance, some laboratory testing involves static aging of samples of the drilling mud at elevated temperatures for a given time period, which could range from about a day to more than about three months. The samples are inspected and evaluated at the end of the time interval to determine the degree to which settlement has occurred. Based on the evaluation, the composition of the drilling mud and/or the temperature at which the drilling mud is statically aged can be adjusted, and then a new sample of drilling mud can re-assessed until a composition suitable for a particular application can be identified. This iterative process can be time consuming may not sufficiently characterize the drilling mud. For example, various operational limits of the drilling mud may not be specifically identified, thus creating challenges for an operator.